Effects of Essential Amino Acid-enriched Whey and Carbohydrate Co-ingestion on Protein Kinetics

Previous work conducted by the Investigators demonstrates that an essential amino acid(EAA)-enriched whey protein combination format is an efficient EAA/protein format to support enhanced whole-body protein balance and sustain muscle protein synthesis compared to isonitrogenous amounts of whey alone or a mixed-macronutrient meal. However, additional work is needed to optimize the formulation to ensure the best possible muscle and whole-body anabolic responses are achieved. This includes addressing the potential value of adding non-EAA/protein components to support energy demands. Providing additional non-protein energy to an EAA-enriched whey protein formulation may reduce the proportion of exogenous amino acids directed towards energy production thereby preserving its use for muscle protein synthesis. However, whether suppressing exogenous amino acid oxidation by providing additional carbohydrate allows for a greater muscle protein synthetic stimulus during moderate energy deficit (- 30% total energy requirements) is unknown. Therefore, this study will test the effects of EAA-enriched whey protein plus carbohydrate versus EAA-enriched whey plus additional EAA using a randomized, cross-sectional longitudinal study design.